The fossil was a 17-million-year-old ostracod, or mussel shrimp. It was one of nearly 800 specimens that Neil had painstakingly handpicked from sediment between 2007 and 2010. Such fossils usually just include the animals’ hard shells, not preserved soft body parts such as inner organs or sperm. But Neil’s samples came from a freshwater cave in Riversleigh, Australia, where millions of years’ worth of bat droppings left the sediment rich in phosphate, which petrified the ostracods’ soft parts.
“I thought that other body parts and organs might be preserved,” Neil says, “but the details were much greater than expected.” However, while he was familiar with their hard parts, Neil didn’t have much experience with analyzing ostracods’ softer tissues. He needed collaborators to fully understand his find.